Originally Posted by jpristel
I haven't seen rust anywhere else on the car. I found another member that posted a while back about having the same issue. As it turns out some drainage holes were clogged on his doors. I'm guessing it could be from washing the car and having trapped water sitting inside the door. The only way to know for sure would be to open it up, but I'm afraid of what I might see.
i guess that could be another possibility

... i would be heading straight to the nearest dealer for an assessment.